Camera Lens Suspension With Limiter

ABSTRACT

A suspension assembly for a camera lens element includes a support member with a wire attach structure and a moving member coupled to the support member. The moving member includes a plate, flexure arms extending from the plate and coupled to the support member, and a wire attach structure. A bearing supports the plate of the moving member for movement with respect to the support member. A shape memory alloy wire is coupled to and extends between the wire attach structures of the support member and the moving member. The limiter limits a range of movement of the moving member with respect to the support member, and in embodiments includes an opening in one of the moving member plate and the support member, and a stop that includes an engagement portion extending into the opening in the other of the moving member plate and the support member. The opening has a first diameter, and the engagement portion has a second diameter that is less than the first diameter.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/951,051, filed Nov. 24, 2015, entitled Camera Lens Suspension withPolymer Bearings, which is incorporated herein by reference in itsentirety and for all purposes, and which claims the benefit of thefollowing U.S. Provisional Applications, both which are incorporatedherein by reference in their entirety and for all purposes: No.62/086,595, filed on Dec. 2, 2014, entitled Improvements to OpticalImage Stabilization (OIS) Camera Lens Suspension, and No. 62/129,562,filed on Mar. 6, 2015, entitled Two-Piece Camera Lens Suspension withIntegrated Electrical Leads.

FIELD OF THE INVENTION

The invention relates generally to camera lens suspensions such as thoseincorporated into mobile phones. In particular, the invention relates tolimiters between relatively movable components of such suspensions.

BACKGROUND

PCT International Application Publication Nos. WO 2014/083318 and WO2013/175197 disclose a camera lens optical image stabilization (OIS)suspension system that has a moving assembly (to which a camera lenselement can be mounted) supported by a flexure element or spring plateon a stationary support assembly. The moving assembly is supported formovement on the support assembly by plural balls. The flexure element,which is formed from metal such as phosphor bronze, has a moving plateand flexures. The flexures extend between the moving plate and thestationary support assembly and function as springs to enable themovement of the moving assembly with respect to the stationary supportassembly. The balls allow the moving assembly to move with littleresistance. The moving assembly and support assembly are coupled byshape memory alloy (SMA) wires extending between the assemblies. Each ofthe SMA wires has one end attached to the support assembly, and anopposite end attached to the moving assembly. The suspension is actuatedby applying electrical drive signals to the SMA wires. Theabove-identified PCT publications are incorporated herein by referencefor all purposes.

There remains a continuing need for improved lens suspensions.Suspension structures of these types that are highly functional, robustand efficient to manufacture would be particularly desirable.

SUMMARY

Embodiments of the invention include a suspension assembly with alimiter. In embodiments, the suspension assembly comprises a supportmember including a wire attach structure, and a moving member coupled tothe support member. The moving member includes a plate, flexure armsextending from the plate and coupled to the support member, and a wireattach structure. A bearing supports the plate of the moving member formovement with respect to the support member. A shape memory alloy wireis coupled to and extends between the wire attach structures of thesupport member and the moving member. The limiter limits a range ofmovement of the moving member with respect to the support member, and inembodiments includes an opening in one of the moving member plate andthe support member, and a stop that includes an engagement portionextending into the opening in the other of the moving member plate andthe support member. The opening has a first diameter, and the engagementportion has a second diameter that is less than the first diameter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top isometric view of a suspension including bearings inaccordance with embodiments of the invention.

FIG. 1B is a top plan view of the suspension shown in FIG. 1A.

FIG. 2A is a top isometric view of the support member of the suspensionshown in FIG. 1A.

FIG. 2B is a bottom plan view of the support member shown in FIG. 2A.

FIG. 3A is a detailed top isometric view of a mount region of thesupport member shown in FIG. 2A.

FIG. 3B is a detailed bottom isometric view of the mount region of thesupport member shown in FIG. 2A.

FIG. 4A is a top isometric view of the moving member of the suspensionshown in FIG. 1A.

FIG. 4B is a bottom plan view of the moving member shown in FIG. 4A.

FIG. 5 is a detailed top isometric view of a flexure arm mount regionand a wire attach of the moving member shown in FIG. 4A.

FIG. 6 is a detailed top isometric view of a flexure arm mounting regionand a wire attach of the moving member shown in FIG. 4A.

FIG. 7 is a detailed top isometric view of a support member mount regionand a flexure arm mount region of the suspension shown in FIG. 1A.

FIG. 8 is a detailed isometric view of one of the bearings shown in FIG.2A.

FIG. 9 is a top isometric view of a suspension in accordance withembodiments of the invention.

FIG. 10 is an exploded isometric view of the suspension shown in FIG. 9.

FIG. 11 is a sectional view of the suspension shown in FIG. 9.

FIGS. 12-18 are annotated illustrations of suspensions that can includethe bearings in accordance with embodiments of the invention.

FIGS. 19-20 describe features of bearings in accordance with embodimentsof the invention.

FIGS. 21-25 are annotated illustrations of suspensions includingbearings in accordance with embodiments of the invention.

FIG. 26A is a top isometric view of a suspension including a limiter inaccordance with embodiments of the invention.

FIG. 26B is a top plan view of the suspension shown in FIG. 1A.

FIG. 27 is a top isometric view of the support member of the suspensionshown in FIG. 26A.

FIG. 28A is a top isometric view of the moving member of the suspensionshown in FIG. 26A.

FIG. 28B is a bottom plan view of the moving member shown in FIG. 28A.

FIG. 29 is a detailed isometric view of a portion of the suspensionshown in FIG. 26A, illustrating embodiments of the limiter.

FIG. 30 is a detailed side view of a portion of the suspension shown inFIG. 26A, illustrating embodiments of the limiter.

DESCRIPTION OF THE INVENTION

FIGS. 1A and 1B illustrate a suspension assembly 10 including bearings100 and sliding bearing interfaces (shown in FIGS. 2A and 8) inaccordance with embodiments of the invention. As shown, the suspensionassembly 10 includes a flexible printed circuit (FPC) or support member12 and a spring crimp circuit or moving member 14 that is coupled to thesupport member. Shape memory alloy (SMA) wires 15 extend between thesupport member 12 and the moving member 14, and can be electricallyactuated to move and control the position of the moving member withrespect to the support member. In embodiments, the suspension assembly10 is a camera lens optical image stabilization (OIS) device that can beincorporated, for example, into mobile phones, tablets, laptopcomputers.

FIGS. 2A, 2B, 3A and 3B illustrate the support member 12 in greaterdetail. As shown, the support member 12 includes a base layer 16 and aplurality of conductive traces 18 such as traces 18 a-18 d in aconductor layer on the base layer. A layer of dielectric 20 is locatedbetween the conductive traces 18 and the base layer 16 to electricallyinsulate the traces from the base layer. A plurality of wire attachstructures such as crimps 24 (i.e., static crimps; four are shown in theillustrated embodiment) are located on the base layer 16. In theillustrated embodiment the crimps 24 are organized as two pairs ofadjacent structures that are integrally formed on a ledge 25 in the baselayer 16 at a level spaced (e.g., in a z-direction) from a major planarsurface portion 26 of the base layer. Other embodiments (not shown)include other wire attach structures (e.g., solder pads) and/or wireattach structures that are organized in other arrangements (e.g., singlyrather than in pairs).

In embodiments, bearings 100, which are described in greater detailbelow, extend from the support member 12 (e.g., from portion 26 of baselayer 16) and engage a bottom side of the moving member 14 (i.e., theside shown in FIG. 4B) to movably support the moving member with respectto the support member. The bearings 100 cooperate with the plate 60 ofthe moving member 14 to provide slidable polymer interfaces between themoving member and the support member 12. In other embodiments, thebearings are mounted to and extend from the moving member 14 to slidablyengage the support member 12. Although three bearings 100 are shown inthe illustrated embodiments, other embodiments have more or fewerbearings.

Traces 18 include terminals 30 and contact pads 32 in the conductorlayer on the base layer 16. Each of the traces 18 couples a terminal 30to a contact pad 32. For example, contact pads 32 a and 32 b are at afirst mount region 33 of the support member 12, and traces 18 a and 18 bcouple terminals 30 a and 30 b to pads 32 a and 32 b, respectively.Contact pads 32 at a second mount region 35 are similarly coupled toterminal 30 by traces 18. A contact pad 32 is located at each of thecrimps 24 in the illustrated embodiment, and each of the contact pads iscoupled by a separate trace to a separate terminal 30 (e.g., trace 18 dcouples terminal 30 d to pad 32 d). The portion of the base layer 16 onwhich the terminals 30 are located is formed out of the plane of themajor surface portion 26 (e.g., perpendicular to the plane of the majorsurface portion in the illustrated embodiment).

FIGS. 3A and 3B illustrate in greater detail embodiments of the mountregion 33 of the support member 12. As shown, the mount region 33includes first and second mounting pads 40 and 42. Mounting pad 42includes an island or pad portion 44 in the base layer 16 that iselectrically isolated from other portions of the base layer. The islandpad portion 44 can be supported in part from adjacent portions of thebase layer 16 by areas of dielectric 20 that extend between the islandpad portion and adjacent portions of the base layer. Trace 18 a andcontact pad 32 a extend to the island pad portion 44, and in embodimentsare electrically connected to the island pad portion 44 by an electricalconnection such as a plated or other via 46 that extends through thedielectric 20 at the mounting pad 42. Other embodiments include otherelectrical connections in place of or in addition to via 46, such as,for example, conductive adhesive that extends between the contact pad 32a and island pad portion 44 over the edges of the dielectric 20.Mounting pad 40 is adjacent to mounting pad 42, and includes a padportion 48 in the base layer 16 (that in embodiments functions as anelectrical ground or common structure), and an electrical connectionsuch as via 50 that connects the contact pad 32 b to the pad portion 48.The mount region 35 can be similar to mount region 33.

FIGS. 4A, 4B, 5, 6 and 7 illustrate embodiments of the moving member 14in greater detail. As shown, the moving member 14 includes a plate 60and spring or flexure arms 62 extending from the plate 60. In theillustrated embodiments, the plate 60 is a rectangular member, and eachflexure arm 62 is an elongated member having first and second portions64 and 66 that extend along two sides of the periphery of the plate. Theplate 60 and flexure arms 62 are formed in a spring metal base layer 68such as stainless steel. Moving member 14 also includes SMA wire attachstructures such as crimps 70 (moving crimps; four are shown in theillustrated embodiment, organized in pairs). In the illustratedembodiment, the crimps 70 are unitary with and formed from the samespring metal base layer 68 as the plate 60 (i.e., on ends of arms 72extending from the plate). Moving member 14 is configured differently inother embodiments. For example, in other embodiments (not shown) theflexure arms 62 can be shaped differently, be different in number,organized differently, and/or can extend from other locations on theplate 60. In still other embodiments (not shown), the crimps 70 can beformed as separate structures that are attached to the plate 60 (i.e.,not unitary with the plate). Other embodiments (not shown) include othertypes of wire attach structures (e.g., solder pads) and/or wire attachstructures that are organized in other arrangements (e.g., singly ratherthan in pairs).

The end portions of the flexure arms 62 have mount regions 74 that areconfigured to be mounted to the mount regions 33 and 35 of the supportmember 12. Conductive traces 76 on the base layer 68 extend on theflexure arms 62 from the mount regions 74. In embodiments, the traces 76also extend on the base layer 68 over portions of the plate 60. In theillustrated embodiment, the traces 76 also extend to contact pads 77 onthe arms 72 on the plate 60. In the illustrated embodiment, the contactpads 77 are on platforms extending out of the major planar surface ofthe plate 60. The contact pads are at other locations (e.g., on theplate 60) in other embodiments (not shown). A layer of dielectric 78 islocated between the conductive traces 76 and the base layer 68 toelectrically insulate the traces from the base layer. Mount regions 74include first and second mounting pads 80 and 82. Each mounting pad 82includes an island or pad portion 84 in the base layer 68 that iselectrically isolated from other portions of the base layer. Each trace76 extends from the mounting pad 82, over (and electrically insulatedfrom) the mounting pad 80. In the illustrated embodiment, the portionsof traces 76 extending between the mounting pads 80 and 82 are enlargedover the portions of the traces on the flexure arms 62 to providesupport for the island pad portions 84 in the base layer 68. The traces76 extend to the island pad portions 84, and in embodiments areelectrically connected to the island pad portions by electricalconnections such as a plated or other via 86 that extends through thedielectric 78 at the mounting pad 82. Other embodiments include otherelectrical connections in place of or in addition to vias 86, such asconductive adhesive that extends between the trace 76 and island padportion 84 over the edges of the dielectric 78. Mounting pad 80 includesa pad portion 90 in the base layer 68 that is electrically isolated fromthe trace 76 by the dielectric 78. In the illustrated embodiments, theportions of the traces 76 over the mounting pads 80 and 82 are circularand open in the center, but take other forms in other embodiments (notshown).

As perhaps best shown in FIGS. 1A and 7, the mount regions 74 of themoving member flexure arms 62 are mechanically attached to the mountregions 33 and 35 of the support member 12. The traces 76 on the flexurearms 62 are electrically connected to the associated traces 18 on thesupport member 12. In embodiments, the mechanical connections are madeby welds between the pad portions 84 and 90 in the base layer 68 of themoving member 14 and the corresponding pad portions 44 and 48 in thebase layer 16 of the support member 12. The welds can, for example, bemade through the openings in the traces 76 at the pad portions 84 and90. The welds also enable electrical connections between the padportions 84 and 90 of the moving member 14 and the corresponding padportions 44 and 48 of the support member 12. By these electricalconnections, the metal base layer 68 of the moving member 14, andthereby the moving crimps 70, are electrically connected in common to anassociated trace 18 (i.e., such as 18 b through via 50). Similarly, eachflexure arm trace 76 is electrically connected to an associated trace 18(i.e., such as 18 a through via 46). Other embodiments of the invention(not shown) have other structures for mechanically mounting the flexurearms 62 to the support member 12, and/or for electrically connecting thetraces 76 on the flexure arms to the associated traces 18 on the supportmember. In the illustrated embodiment, conductive metal regions 94 arelocated directly on the metal base layer 68 of the moving member 14 atthe crimps 70 (i.e., there is no dielectric or other insulating materialbetween the conductive metal regions and the metal base layer) toenhance the electrical connections between the metal base layer and theSMA wires 15 engaged by the crimps.

As described in greater detail below, the support member 12 and movingmember 14 can be formed from additive and/or subtractive processes. Baselayers 16 and/or 68 are stainless steel in embodiments. In otherembodiments the base layers 16 and/or 68 are other metals or materialssuch as phosphor-bronze. Traces 18 and 76, terminals 30 and contact pads32 can be formed from copper, copper alloys or other conductors.Polyimide or other insulating materials can be used as the dielectric 20and 78. Other embodiments of the support member 12 and/or moving member14 (not shown) have more or fewer traces 18 and 76, and the traces canbe arranged in different layouts. Structures other than crimps 24, suchas welds, can be used to attach the SMA wires 15 to the base layer 16.Other embodiments of the invention (not shown) have more or fewer crimps24 and 70, and the crimps can be at different locations on the supportmember 12 and moving member 14, respectively.

FIG. 8 is a detailed illustration of a portion of the support member 12including a bearing 100. As shown, the bearing 100 includes a spacerportion 102 and a polymer surface region or portion 104. The spacerportion 102 extends from the base layer 16 of the support member 12 toposition the surface portion 104 at a height with respect to the supportmember 12 that will allow the portion of the moving member 14 engaged bythe surface portion (e.g. plate 60) to slide on the bearing 100 (e.g., aheight of 25-200 μm in embodiments). The spacer portion 102 and thepolymer surface portion 104 can be a one-piece polymer member inembodiments. Properties of the polymer surface portion 104 (andoptionally the spacer portion 102) can include relatively low friction,relatively low wear and/or relatively high stiffness. In one embodiment,spacer portion 102 and polymer surface portion 104 are formed frommaterials such as POM (polyoxymethylene). Surface portion 104 is formedfrom other polymers such as fluoropolymers (e.g., Teflon) in otherembodiments. Bearing 100 can be fixedly attached to the support member12 by adhesive 106 (e.g., thermoset adhesive, 5-25 μm thick inembodiments). In other embodiments, the bearing 100 is attached tosupport member 12 by other methods or structures such as by welding. Inthe illustrated embodiment the bearing 100 is attached to the supportmember 12 in a partial-etched pocket 108 in the base layer 16. In yetother embodiments the bearing 100 is attached to a surface portion ofthe base layer 16 that is free from a pocket such as 108.

In still other embodiments, the spacer portion 102 can be formed fromother materials such as metal, and the surface portion 104 can be alayer or coating of polymer on the metal spacer portion. For example, inembodiments the spacer portion 102 can be a formed dimple in the metalbase layer 16. In other embodiments the spacer portion 102 is a separatemetal or polymer member that is attached, for example by adhesive orwelding, to the support member 12. In still other embodiments, thebearings 100 can extend from the moving member 14 (e.g., from the baselayer 68), and slidably engage the support member 12 (e.g, at the baselayer 16). Surface portion 104, which has a perimeter, can be generallyflat as shown in the embodiment of FIG. 8. In other embodiments thesurface portion 104 has other shapes such as a convex shape. Thesurfaces engaged by the bearing can be metal, and can be processed bylaser polishing, electro polishing or other methods to provide a lowsurface roughness and further reduce friction at the sliding bearinginterface. Yet other embodiments include lubricant such as Xylan at thesliding bearing interface.

Bearings such as 100 provide important advantages. For example, inaddition to providing a high-quality, reliable, low friction slidingbearing interface, they can be manufactured and assembled relativelyefficiently, and enable relatively close spacing between the supportmember 12 and moving member 14 (i.e., relatively thin suspensions).

FIGS. 9-11 illustrate a suspension assembly 110 having bearings 200 inaccordance with embodiments of the invention. As shown, suspensionassembly 110 includes a can base 111, flexible printed circuit (FPC) orsupport member 112, bearing race 113, moving member 114 and moving crimp115. Features of suspension assembly 110 can be similar to those ofsuspension assembly 10 described above. Support member 112 includes aplurality of wire attach structures such as static crimps 124. Bearingrace 113 can be a polymer member and has polymer bearing plate surfaceportions 203. The bearing race 113 is fixedly attached to can base 111and/or support member 112 (e.g., by adhesive or welds). Properties ofthe polymer surface portions 203 (and optionally other portions of thebearing race 113) can include relatively low friction, relatively lowviscosity, relatively low wear and/or relatively high stiffness. In oneembodiment, bearing race 113 and polymer surface portions 203 are formedfrom materials such as POM (polyoxymethylene). Bearing race 113 and/orsurface portions 203 are formed from other polymers such asfluoropolymers (e.g., Teflon) in other embodiments. As shown in FIG. 11,a screening can 117 can be attached to the can base 111 and encloseportions of the suspension assembly 110.

Moving member 114 includes a plate 160 and spring or flexure arms 162extending from the plate. Plate 160 and flexure arms 162 are formed froma spring metal layer such as stainless steel. End portions of theflexure arms 162 have mount regions 174 configured to be mounted tomount regions 133 of the support member 112. Moving crimp 115 includeswire attach structures such as crimps 170, and is attached (e.g., bywelding) to the plate 160 of moving member 114 to become part of themoving member. Although not shown in FIGS. 9-11, SMA wires are attachedto and extend between associated crimps 124 on the support member 112and crimps 170 on the moving crimp 115.

Bearings 200 include a spacer portion 202 and have a surface region orportion 204. The spacer portion 202 extends from the plate 160 of themoving member 114, and the surface portion 204 engages a polymer surfaceportion 203 on the bearing race 113 to define a sliding bearinginterface that will allow the moving member 114 to slide with respect tothe bearing race and the support member 112. Properties of the spacerportion 202 and surface portion 204 can include relatively low friction,relatively low viscosity, relatively low wear and/or relatively highstiffness. In the illustrated embodiment, the spacer portion 202 is aformed dimple in the plate 160. In other embodiments the spacer portion202 is a separately manufactured member (e.g., from metal, polymer orceramic) that is attached to the plate 160 (e.g., by adhesive orwelding). In embodiments, for example, the spacer portion 202 andsurface portion 204 are formed from polyoxymethylene. In embodiments,the surface portion 204 can be a coating on the spacer portion 202.Examples of materials that can be used as coatings for surface portion204 include ceramic, and polymers such as polyoxymethylene andfluoropolymers (e.g. Teflon). Although three bearings 200 are shown inFIG. 10, other embodiments have fewer or more bearings. Surface portions203 and/or 204 can be processed, for example by laser polishing orcoining, to enhance the smoothness of the surfaces. Bearings 200 offeradvantages similar to those of bearings 100 described above.

FIGS. 12-18 are annotated illustrations of an improved camera lenssuspension assembly in accordance with embodiments of the invention. Thesuspension assembly has two primary components—a base or support member(referred to in FIGS. 12-18 as a static FPC (flexible printed circuit)),and a moving/spring member (referred to in the FIGS. 12-18 as a springcrimp circuit). Both the static FPC (base member) and the spring crimpcircuit (moving member) are integrated lead structures in theillustrated embodiments, in that they have electrical structures such asleads, contact pads and terminals (e.g. in a copper “Cu” or copper alloylayer) formed on the base metal (stainless steel (SST)) in theillustrated embodiments). A layer of insulator (e.g., polyimide or“poly”) separates the portions of the electrical structures that are tobe electrically isolated from the SST (other portions of the Cu layerare connected to or directly on the SST layer). At some locations, theelectrical structures can be electrically connected to the SST layer byelectrical connections (e.g., “vias”) extending from the Cu trace orlead layer to the SST layer through openings in the poly layer. Inembodiments, a lens can be mounted to the spring crimp circuit. In yetother embodiments, an autofocus system supporting the lens can bemounted to the spring crimp circuit.

As noted above, the static FPC and spring crimp circuit can be formedfrom overlaying layers of base metal (e.g., a spring metal such as SST),poly and Cu (i.e., the “trace” layer). An insulating covercoat can beapplied over all or portions of the Cu. Corrosion resistant metals suchas gold (Au) and/or nickel (Ni) can be plated or otherwise applied toportions of the trace layer to provide corrosion resistance.Conventional additive deposition and/or subtractive processes such aswet (e.g., chemical) and dry (e.g., plasma) etching, electro plating andelectroless plating and sputtering processes in connection withphotolithography (e.g., use of patterned and/or unpatterned photoresistmasks), as well as mechanical forming methods (e.g., using punches andforms) can be used to manufacture the static FPC and spring crimpcircuit in accordance with embodiments of the invention. Additive andsubtractive processes of these types are, for example, known and used inconnection with the manufacture of disk drive head suspensions, and aredisclosed generally in the following U.S. patents, all of which areincorporated herein by reference for all purposes: Bennin et al. U.S.Pat. No. 8,885,299 entitled Low Resistance Ground Joints for Dual StageActuation Disk Drive Suspensions, Rice et al. U.S. Pat. No. 8,169,746entitled Integrated Lead Suspension with Multiple Trace Configurations,Hentges et al. U.S. Pat. No. 8,144,430 entitled Multi-Layer Ground PlaneStructures for Integrated Lead Suspensions, Hentges et al. U.S. Pat. No.7,929,252 entitled Multi-Layer Ground Plane Structures for IntegratedLead Suspensions, Swanson et al. U.S. Pat. No. 7,388,733 entitled Methodfor Making Noble Metal Conductive Leads for Suspension Assemblies,Peltoma et al. U.S. Pat. No. 7,384,531 entitled Plated Ground Featuresfor Integrated Lead Suspensions.

The static FPC is a one-piece member in the illustrated embodiment, andhas two static crimps (attachment structures) on each of two diagonalcorners of the member (4 static crimps in total). A terminal pad sectionincludes terminal pads in the trace layer that are connected to tracesthat extend over the surface of the member. As shown for example, aseparate trace extends to each of the four static crimps. At each of thestatic crimps is an electrical contact or terminal formed by the traceand poly layers. Formed dimples extending from the upper surface of thestatic FPC member engage the back surface of the spring crimp circuitmember, and function as sliding interface bearings to enable lowfriction movement of the spring crimp circuit member with respect to thestatic FPC. The traces on the static FPC also couple terminal pads toelectrical pad locations on the static FPC that are electrically andmechanically coupled to the spring crimp circuit member (e.g., toprovide electrical signals to an auto focus (AF) assembly and to providea common or ground signal path to the SST layer of the spring crimpcircuit member. Vias couple the respective traces on the static FPC toportions of the SST layer that are connected to the feet.

The spring crimp circuit is a one-piece member in the illustratedembodiments and includes a central member for supporting a lens or autofocus system, and one or more spring arms (two in the illustratedembodiment) extending from the central member. The spring crimp memberhas two moving crimps on each of two diagonal corners of the member (4moving crimps in all). Pedestals or feet in the SST layer (on the endsof the spring arms opposite the central member in the illustratedembodiment) are configured to be welded or otherwise attached tocorresponding locations on the static FPC. Traces on the spring crimpmember are configured to be electrically coupled to traces on the staticFPC (e.g., through the feet) and couple signals to terminal pads such asthe auto focus (AF) terminal pads. In the illustrated embodiment, theSST layer of the spring crimp circuit is used as a signal path to theends of the SMA wires attached to the moving crimps. Electricalconnection between the corresponding terminal pad and trace on thestatic FPC to the SST layer of the spring crimp circuit is provided bythe connection between the feet of the spring arms and the SST layer ofthe static FPC (i.e., the SST layers of the two members are electricallycoupled, and are at a common ground potential in embodiments).

Suspensions in accordance with the invention having traces on the movingmember flexure arms offer important advantages. They can for example, beefficiently fabricated and assembled. The traces are effectivestructures for coupling electrical signals to structures mounted to theplate or other portions of the moving member.

FIGS. 26A, 26B, 27, 28A, 28B and 29-30 illustrate a suspension assembly10′ that includes a crash stop or limiter 210 in accordance withembodiments of the invention. Other than the limiter 210, features ofsuspension 10′ can be similar to or the same as other embodiments of theinvention, including suspension 10 described above. Limiter 210 can alsobe incorporated in any or all other described embodiments of theinvention.

As shown, the limiter 210 includes an engaged structure such as opening212 on or in the plate 60′ of the moving member 14′, and a stop 214 onthe support member 12′ (e.g., on a planar portion of the supportmember). An engagement portion 206 of the stop 214 is fixedly positionedwith respect to the support member 12′ and extends into the opening 212.A first diameter of the opening 212 is greater than a second diameter ofthe engagement portion 206, allowing a limited range of motion of themoving member 14′ with respect to the support member 12′ (e.g., indirections generally parallel to the major planar surfaces of the movingmember and support member). Features of limiter 210 such as the shapes,sizes and locations of the opening 212 and stop 214 are configured toprevent displacement of the moving member 14′ with respect to thesupport member 12′ that might cause damage to the suspension 10′components or other components, such as a lens, mounted to thesuspension. The engagement portion 206 can move within a predeterminedrange of movement, but engages the engaged structure such as the wallportions of the plate 60′ defining the opening 212 to limit the range ofrelative movement.

In embodiments, the engagement portion 206 is on a spacer portion 208.The spacer portion 208, which can be integral with and/or formed fromthe same material as the engagement portion 206, is larger than theengagement portion in embodiments, and provides a base for theengagement portion to extend or otherwise position the engagementportion away from the major planar surface of the support member 12′.The engagement portion 206 is on an end of the spacer portion 208opposite the major planar surface of the support member 12′. Inembodiments, the stop 214 can be a separately manufactured polymermember that is attached to the support member 12′ (e.g., by adhesive).In other embodiments the stop 214 can be a metal member formed from oneor more layers of the support member 12′ (e.g., from the base layer16′), or a separately manufactured member that is attached to thesupport member during assembly (e.g., by welding). In still otherembodiments the stop 214 can be integral with other suspensioncomponents such as the bearing such as that shown at 100. Although twolimiters 210 are shown in the illustrated embodiment, other embodimentshave more or fewer limiters. Opening 212 can be a through hole as shownin the illustrated embodiment, or a recess or pocket (e.g., formed bypartial etching). In still other embodiments the opening 212 can be onthe support member 12′ and the stop 214 can be on the moving member 14′.Limiters such as 210 provide important advantages. For example, they canprevent damage to the suspension or components mounted thereto (e.g.,when the device in which it is incorporated is dropped). Suspensionsincluding the limiters can also be efficiently manufactured.

In embodiments, the suspension assembly comprises: (1) a support memberincluding a wire attach structure; (2) a moving member coupled to thesupport member, including: (i) a plate; (ii) flexure arms extending fromthe plate and coupled to the support member; and (iii) a wire attachstructure; (3) a bearing supporting the plate of the moving member formovement with respect to the support member; (4) a shape memory alloywire coupled to and extending between the wire attach structures of thesupport member and the moving member; and (5) a limiter to limit a rangeof movement of the moving member with respect to the support member, thelimiter including: (i) an opening in one of the moving member plate andthe support member, wherein the opening has a first diameter; and (ii) astop on the other of the moving member plate and the support member, thestop including an engagement portion extending into the opening, whereinthe engagement portion has a second diameter that is less than the firstdiameter. In embodiments, the stop further includes a spacer portion,and wherein the engagement portion is on an end of the spacer portion.In embodiments, the spacer portion is formed from the support member. Inembodiments, the spacer portion is formed as a member separate from thesupport member, and is mounted to the support member. In embodiments,the opening is a through hole in the plate of the moving member.

Although the invention has been described with reference to preferredembodiments, those of skill in the art will recognize that changes canbe made in form and detail without departing from the spirit and scopeof the invention. For example, although the illustrated embodimentsinclude the traces on the sides of the flexure arms opposite the supportmember (i.e., on the top side of the traces), other embodiments canalternatively or in addition include traces on the sides of the flexurearms facing the moving member (i.e., on the bottom side of the traces).Although described in connection with certain suspension assemblyembodiments, bearings 200 and 100 can be incorporated in othersuspension assembly embodiments. Bearings in accordance with embodimentsof the invention can be used in combination, and/or in connection withor as an alternative to ball bearings to provide for relative movementbetween suspension components. Features of bearings 100 and 200 can becombined with each other.

What is claimed is:
 1. A suspension assembly, comprising: a supportmember including a wire attach structure; a moving member coupled to thesupport member, including: a plate; flexure arms extending from theplate and coupled to the support member; and a wire attach structure; abearing supporting the plate of the moving member for movement withrespect to the support member; a shape memory alloy wire coupled to andextending between the wire attach structures of the support member andthe moving member; and a limiter to limit a range of movement of themoving member with respect to the support member, the limiter including:an opening in one of the moving member plate and the support member,wherein the opening has a first diameter; and a stop on the other of themoving member plate and the support member, the stop including anengagement portion extending into the opening, wherein the engagementportion has a second diameter that is less than the first diameter. 2.The suspension assembly of claim 1 wherein the bearing includes: aspacer portion extending from one of the support member and the plate ofthe moving member; and a polymer interface surface portion slidablyengaged with the other of the support member and the plate of the movingmember.
 3. The suspension assembly of claim 1 wherein the stop furtherincludes a spacer portion, and wherein the engagement portion is on anend of the spacer portion.
 4. The suspension assembly of claim 3 whereinthe spacer portion is formed from the support member.
 5. The suspensionassembly of claim 4 wherein the bearing includes: a spacer portionextending from one of the support member and the plate of the movingmember; and a polymer interface surface portion slidably engaged withthe other of the support member and the plate of the moving member. 6.The suspension assembly of claim 3 wherein the spacer portion is formedas a member separate from the support member, and is mounted to thesupport member.
 7. The suspension assembly of claim 6 wherein thebearing includes: a spacer portion extending from one of the supportmember and the plate of the moving member; and a polymer interfacesurface portion slidably engaged with the other of the support memberand the plate of the moving member.
 8. The suspension assembly of claim1 wherein the opening is a through hole in the plate of the movingmember.
 9. The suspension assembly of claim 8 wherein the bearingincludes: a spacer portion extending from one of the support member andthe plate of the moving member; and a polymer interface surface portionslidably engaged with the other of the support member and the plate ofthe moving member.